• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.4 no.2
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• pp.20-28
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• 2008

According to IAEA regulations, a transportation package of radioactive material should perform its intended function of containing the radioactive contents after the drop test, which is one of hypothetical accident conditions. Impact limiters attached to a transport cask absorb the most of impact energy. So, it is appreciated to determine properly the shape, size and material of impact limiters. A material data needed in this determination is a dynamic one. In this study, several materials considered as those of impact limiters were tested by a drop weight facility to acquire dynamic material characteristics data. Impact absorbing volume of the impact limiter was derived mathematically for each drop condition. A size optimization of impact limiter was conducted. The derived impact absorbing volumes were applied as constraints. These volumes should be less than critical volumes generated based on the dynamic material characteristics. The derived procedure to decide the shape of impact limiter can be useful at the preliminary design stage when the transportation package's outline is roughly determined and applied as input value.

• Journal of Korean Society for Geospatial Information Science
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• v.1 no.2 s.2
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• pp.167-175
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• 1993

This article contains three objectives. First it is to revise unnecessary procedures of a transportation models and transform results of a model into an image. Second objectives is to develop an operational structures which automatically input all data needed from arc-node topology to link-node topology of transportation network. By solving the network discrepancy, time and money for constructing to transportation can be saved. In addition, the rate of errors that my caused during data input process can be reduced. Conclusively, it is found that the integration package may provide user friendliness and reduce the rate of errors. The package can extract informations such as distance between zones and nodes, lane numbers, and hierarchy from arc-node topology for executing SDI. Another advantage of integration is the ability of spatial analysis. The integrated package may provide adequate arrangements of traffic facilities and checking systems of the shortest path. Finally, the database function of GIS package provides various information about study area for transportation analysis.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.3
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• pp.216-223
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• 2016

This paper proposes a new controller design method for a fork-type lifter (FTL) of a transportation mobile robot. The transportation robot needs to pick up a package from a stack on a storage shelf and move on by a planned path in a logistics center environment. The position of the storage shelf is recognized by reading a QR code on the floor, and using this position, the robot can move to reach the storage shelf and pick up the package. PID controllers and an adaptive controller are designed to control the velocity of two wheels and the position of the FTL. An adaptive controller for the lifter is designed to elevate up and down on a slideway to the correct height position of the package on the stack of the storage shelf. The simulation results show that the PID controllers can respond smoothly to the desired angular velocity and the adaptive controller can adapt quickly and correctly to the desired height.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.223-230
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• 2015

As the Transportation Simplex Method of the general transportation problem are inapplicable to the large-scale unbalanced transportation problem, a commercialized linear programming package remains as the only viable means. There is, however, no method made available to verify the optimality of solutions attained by the package. This paper therefore proposes a simple heuristic algorithm to the large-scale unbalanced transportation problem. From a given problem of $31{\times}15$supply and demand areas, the proposed algorithm determines the number of demands areas for each supply area and executes on the latter in the ascending order of each of their corresponding demand areas. Next, given a single corresponding demand area, it supplies the full demand volume and else, it supplies first to an area of minimum associated costs and subsequently to the rest so as to meet the demand to the fullest extent. This initial optimal value is then optimized through an adjustment process whereby costs are minimized as much as possible. When tested on the $31{\times}15$cost matrix, the proposed algorithm has obtained an optimal result improved from the commercial linear programming package by 8.9%.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.181-188
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• 2021

In preparing a aggregate production plan(APP), the transportation method generally uses a linear planning(LP) software package for TSM(transportation simplex method), which seeks initial solutions with either NCM, LCM, or VAM specialized in transportation issues and optimizes them with either SSM or MODI. On the other hand, this paper proposes a transportation method that easily, quickly, and accurately prepares a APP without software package assistance. This algorithm proposed simply assigned to least cost-first, and minimized the inventory periods. Applying the proposed algorithm to 6-benchmarking data, this algorithm can be obtained better optimal solution than VAM or LP for 4 data, and we obtain the same results for the remained 2 data.

• Journal of Korean Society for Geospatial Information Science
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• v.3 no.2 s.6
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• pp.199-211
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• 1995

Bus, Which is together with subway the main part of public transportation modes in the city, is reviewed for the development of an optimal feeder-bus service area. Based on the IDRISI of GIS package, and taking into account of the convenience of downtown-oriented public transportation users at peak time, a model for the development of feeder-bus service area and a solution and introduced. Major result in this study is as follows: Development is given to a model that is designed to overcome the shortage of the existing models, which has limits in simulating the real situation; Variables were used in combination so that bus and subway route, station spacing, and operating frequency can be determined simultaneously, which enables to elucidate the mutual relationship and the structure in public transportation system. A model for feeder-bus area development is also given applied to determination and opening of subway and urban express bus route and new transportation systems. The model developed in this paper is useful in the case of extension and opening of subway and urban express bus route and new transportation Systems.

• The monthly packaging world
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• s.105
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• pp.168-177
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• 2002

• The monthly packaging world
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• s.308
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• pp.54-58
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• 2018

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.2
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• pp.128-135
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• 2004

Generally, heavy electronic products undergo many different types of shocks in transportation from a manufacturer to customers. Cushioning package is used to protect electronic products from severe shock environments. Since the mass distribution of heavy electronic products is usually unbalanced and complex. it is very difficult to design a cushioning package with having high performance by considering only the equivalent stiffness of that. Therefore, when designing the cushioning package for a heavy electronic product, it is necessary to optimize its shape in order to maximize the cushioning performance. In this study, it is focused on designing an optimal shape of cushioning package for a large refrigerator and an efficient design method is suggested by using a dynamic finite element analysis. As the results of this study the optimal shape of cushioning package, which has high cushioning performance and minimized volume, was obtained through the mechanical drop analysis and a optimization process. Through free drop tests of refrigerators, it was identified that the cushioning performance of the cushioning package was improved up by 25% and the its own volume was reduced by 22 ％.

• Journal of Aerospace System Engineering
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• v.15 no.4
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• pp.11-20
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• 2021

The estimation of hovering flight time of multicopters using the battery power propulsion system is important for the development and design of the aircraft and its operation. For a given operational weight, the maximum possible battery weight can be decided using both a conventional energy density method and a new Peukert law. In the present study, the hovering flight time is predicted using both methods. The specific data of multicopters in the published literatures were employed for the computation of the hovering flight time. The results were validated with the measured data. The effect of figure of merit of propeller, battery discharging process on the hovering flight time was evaluated, Finally, the effect of the battery cell and package connection types on the hovering time was investigated. It was found that the combination of serial battery cell connections and parallel package connection is the bast in the endurance maximization aspect. As the cell number increases in a package, the hovering flight time is increased. There exists the max. battery ratio for the given takeoff gross weight.